A drawworks apparatus is a type of winch used in the oil well drilling and service industry as a portion of a drilling or servicing rig to raise and/or lower items such as tools, equipment and lengths of pipe from a well bore from which oil or other hydrocarbons are produced.
The drawworks typically includes a large-diameter spool that typically supports a length of cable, a drive system connecting the spool to a power source, one or more brakes and other auxiliary devices that may assist in the lowering and raising items into a well bore. In certain drawworks apparatus, a band brake system having brake flanges mounted located externally on one or both ends of the drum barrel may be used to reduce the rotational speed of the drum barrel.
However, major disadvantages plague conventional drawworks designs. For instance, there is no manner in which to actively cool the brake flanges mounted. Particularly, there is no manner in which to supply a cooling fluid from a rotating union to the brake assembly.
The lack of a cooling system may lead to overheating of the brakes during operation, which in turn, will cause an inordinate amount of wear on the brakes. Such wear will reduce the operating life of the brake assembly, thereby requiring frequent maintenance to either repair and/or replace the brake flanges. Such maintenance leads to increased operating costs.
Moreover, the lack of a cooling system may lead to total mechanical failure of the brake system. Such failure may result in several undesirable consequences. For instance, brake failure during operation of the drawworks may result in the loss of tools, equipment and piping. Secondly, the brake failure will require replacement of the brakes, which, in turn, will require halting the entire drilling operation. Accordingly, the overall operating costs will significantly increase. Even still, the lack of an effective brake cooling system will inevitably reduce the amount of loads the drawworks apparatus may be able to manage due to the increased heat.